Air biased magazine lock and guideway closure for fastener driving tools

ABSTRACT

An air lock and positioning device for the magazine slide and guideway closure of a fastener driving tool, the advantageous features thereof being a substantial reduction in size accompanied by improved locking action and increased safety, whereby readjustment of the magazine slide and guideway closure is continuously affected during operation so as to assure tightness and consequent accurate guideway dimensions, and all of which is accomplished with few and easily formed parts.

United States Patent 1191 Powers 1 1 May 22, 1973 [54] AIR BIASEDMAGAZINE LOCK AND 3,610,505 10 1971 Males ..227 123 GUIDEWAY CLOSURE FORFASTENER 3 22% DRIVING TOOLS 314911931 1/1970 Sales ..227 127 [7 5]Inventor: Richard E. Powers, San Marino,

Calif.

[73] Assignee: Powers Wire Products Co., Inc., El

Monte, Calif.

[22] Filed: May 21,1971

[21] Appl. No.: 145,755

[52] U.S. Cl. ..227/127 [5 1] Int. Cl. ..B27f 7/08 [58] Field ofSearch.....' ..227/l20,. 123, 127

[56] References Cited UNITED STATES PATENTS 3,140,492 7/1964 Bade..227/l23 Primary ExaminerGranville Y. Custer, Jr. Attorney-William H.Maxwell [57] ABSTRACT An air lock and positioning device for themagazine slide and guideway closure of a fastener driving tool, theadvantageous features thereof being a substantial reduction in sizeaccompanied by improved locking action and increased safety, wherebyreadjustment of the magazine slide and guideway closure is continuouslyaffected during operation so as to assure tightness and consequentaccurate guideway dimensions, and all of which is accomplished with fewand easily formed parts.

14 Claims, 13 Drawing Figures Patented May 22, 1933 3,734,379

4 Sheets-Sheet :1

Fla. [2. 26

AIR BIASED MAGAZINE LOCK AND GUIDEWAY CLOSURE FOR FASTENER DRIVING TOOLSBACKGROUND The present invention is concerned with air operated toolsfor driving fasteners such as staples and nails or the like, wherein airstored under pressure is released in a cylinder and piston motor tooperate a driver blade into driving engagement with fastenerssequentially supplied from a magazine. These tools operate explosivelyso as to strike the fasteners and to hammer them into work with a singleblow, removing said fasteners one at a time from a magazinesupplythereof. It is customary for such a magazine to handle a stack offasteners, usually in stick form wherein a multiplicity of fasteners areseverably held together in straight columnar formation, and for such atool to be characterized by a head with a guideway therethrough adaptedto receive individual fasteners from the magazine and to guide them intothe work. In dealing with tools and the driving of fasteners of the typeunder consideration, and because of obstructions in the work or otherdiscrepancies, there are malformations of the fasteners and the jammingthereof in the transmission of the fastener from said magazine and intosaid work; and for these reasons it is highly advantageous to carry theguideway closure on the magazine slide for retractibility from the headupon withdrawal of said slide. This cooperative relationship opens upthe entire workings of the tool and enables the guideway and magazine tobe cleared with facility; however problems arise in locking of theguideway closure in tight engagement with the head to thereby completean accurately cross sectioned guideway. Heretofore these slides havebeen mechanically locked with various types of spring latchesincorporated in the rear portion of the magazine and usually an extendedportion making the tool unnecessarily cumbersome. Also, the tightness ofthe guideway closure has been dependent upon the tolerances and wear inthe latch mechanisms, and always prone to accidental release. It istools of the type thus far referred to which are improved by utilizingthe present invention therein.

FIELD OF INVENTION This invention relates to an air lock for the slideof a magazine in a pneumatic tool for driving fasteners that issue outof said magazine and into a guideway completed by a closure elementcarried by said slide and positioned by the instant air lock, it being ageneral object of this invention to provide a most effective lockinvolving the fewest simply formed parts and all of which isincorporated in existing and/or required body structure withoutencumbering the tool. And as compared with like prior art tools, thetool hereinafter dis closed is of reduced size, is less cumbersome andis safer to use as a result of incorporating the present inventiontherein, and furthermore is self-adjusting so as to compensate formanufacturing tolerances and wear.

An object of this invention is to reduce the size of the magazine intools of the type under consideration, specifically by shortening thesame through the elimination of the usual space consuming mechanicallatches and replacing the same with a compact air pressure biased latchcomprising a single moving part. The pneumatic latch hereinafterdisclosed is initially biased by a light spring and is forcefully biasedinto operating position by the working air pressure applied to the tool,thereby discouraging anything except deliberate manual disengagement.

Another object of this invention is to utilize the consistent bias ofair pressure supplied to tools of the type under consideration andapplied to a self-locking wedge means disposed at a releasable angle andwhich advances and firmly positions the guideway closure of the tool,holding it fixedly positioned without play.

It is still another object of this invention to provide an improveddrive head and magazine mount onto the light weight frame of a fastenerdriving tool of the type under consideration. With the presentinvention, the frame is of light-soft metal whereas the magazine is of aheavier-durable metal and the drive head of heavierhard metal; the saidframe being provided with mounting lugs clamped between the magazine andhead by means of fasteners engaged and threaded with the more durableparts, and the head positioned by means of an extension thereofprojecting into a complementary window in the cylinder head of theframe.

DRAWINGS The various objects and features of this invention will befully understood from the following detailed description of the typicalpreferred form and application thereof, throughout which descriptionreferenceis made to the accompanying drawings, in which:

FIG. 1 is a longitudinal cross sectional view taken through an airoperated fastener driving tool, illustrating the air biased magazinelock and guideway closure therefor. FIG. 2 is a fragmentary view of aportion of the structure shown in FIG. 1, illustrating opening of theguideway closure; and FIG. 3 is a fragmentary view illustrating themagazine lock operated so as to permit the movement of parts shown inFIG. 2. FIG. 4 is an enlarged detailed sectional view taken as indicatedby line 44 on FIG. 1. FIG. 5 is an enlarged fragmentary view of themagazine lock elements, positioned as shown in FIG. 1, and illustratingthe directions of force and adjustment. FIG. 6 is an enlarged sectionalview showing the air release of the tool; while FIG. 7 is an enlargeddetailed view showing the manually operable button that controls therelease. FIG. 8 is an enlarged detailed sectional view taken asindicated by line 88 on FIG. 1. FIG. 9 is a rear quarter perspectiveview illustrating a unique facer that is inserted into the headconstruction. FIG. 11 is a sectional view taken as indicated by linel1l1 on FIG. 8.; FIG. 10 is a perspective view illustrating the frame ofthe head construction which receives the elements illustrated in FIGS. 8and 9. FIG. 12 is a rear quarter perspective view illustrating the headper se which cooperatively receives the facer shown in FIG. 9. And, FIG.13 is an enlarged detailed sectional view taken as indicated by line13-13 on FIG. 1.

v PREFERRED EMBODIMENT A percussively operable cylinder and piston motorand air return means therefor may be used in connection with the airbiased magazine lock and guideway closure hereinafter described and,therefore, in the drawings I have illustrated this type of tool. It isto be understood, however, that the present invention is not limited tothis particular tool and may be employed to advantage with any fluidpressure actuated tool having a magazine supply of elements to beprocessed and particularly with those tools wherein the guideway iscovered by a removable closure.

The tool, as illustrated in the drawings, is adapted to be handledmanually and involves, generally, a frame A having a body portion and ahandle or grip portion 11, a head B carried by the frame A and adaptedto direct fasteners into a piece of work, a cylinder C adapted to befixed in the frame A and cooperating therewith to establish an airreturn means adapted to be charged with fluid under pressure at the endof the work stroke, a piston D adapted to reciprocably operate in thecylinder C and coupled to a driver blade E, there being a snubber Fadapted to arrest the piston D and driver blade E and to seal with thepiston D at the end of the work stroke, an air release means G adaptedto cooperate with the cylinder C and control operation of the piston D,a magazine H for handling a supply of fasteners such as staples to bereceived by and delivered through the head, and in accordance with theinvention an air biased magazine safety lock and guideway closureadjuster means X having a readjustable locking action during operationof the tool.

The frame A carries the various elements of the tool, and is shown inthe configuration of a light tacker adapted to be conveniently handled.The frame A involves, generally, the body portion 10 and the handle orgrip portion 11, the body portion 10 being a simple elongate part havinga cylinder chamber 12 extending longitudinally thereof and having awindow 14 through the cylinder head 15 thereof at the lower end of thecylinder chamber 12 for receiving and positioning the head B. The windowis preferably polygonal and is shown to be rectangular in cross section,substantially greater than the guideway cross section, having opposedpairs of parallel walls 16 and 17 normal to the top and bottom 18 of thehead 15. In practice, the frame A is made of a light weight softer metalwhile the head B is made of a heavy and durable heat treated metal; inwhich case the head B is provided with an extension that projects intothe window 14 to be located thereby in order to position the guidewayconcentric with the drive axis of the tool. Accordingly, the window 14opens transversely of the head 15, with side walls 16, and with frontand rear walls 17; the latter rear wall 17 being coplanar with the frontfaces 20 of spaced and depending mounting lugs 19 adapted tocooperatively mount both the head B and magazine A as hereinafterdescribed. A facer 21 of durable metal (such as that of the head) coversthe wall 17 and faces 20, the portion thereof covering the wall 17establishing a wall of the guideway, and the portions thereof coveringthe faces 20 engageably receiving the rear face of the head to positionthe same. The handle or grip portion 11 is provided to give the personhandling the tool a convenient means to hold the tool and is a simplegrip of chambered construction that projects at a right angle from thebody 10. In practice, the grip 11 is hollow and forms an air pressureaccumulator as clearly shown in FIG. 1 of the drawings, and projectslaterally from the upper portion of the body 10 a full hands width andmore. And, in accordance with the present invention, a strut 22 dependsfrom the outer butt end of the grip portion 11 and which ischaracterized by a bottom 18' coplanar with the bottom 18 of thecylinder head 15.

In structures of the type under consideration, it is common practice toprovide a fluid and lubricant mist pressure supply connection 23 at thegrip Ill, such as a pneumatic hose or the like, and also to include acontrol means I at the grip 11. It is to be understood that such a fluidpressure supply is provided and connected with the grip 11 so as tocharge the chamber therein.

The head B is in effect, an extension of the body 10 of the frame A andis provided to receive and guide fasteners such as staples to the workbeing acted upon by the tool. The head B is carried by the body in thewindow 14 and is provided with a longitudinal guideway 27 that extendsthrough and below the cylinder head 15. The head B has a seat 24 engagedupon the bottom 18 and it has a front end face 25 engageable with thework, and in accordance with the present invention it has a rectangularextension 26 that projects upwardly from seat 24 and occupies the window14. In the particular form of the invention shown, the guideway 27 isadapted to handle fasteners or staples S that are U- shaped and formedof wire, or the like, having a pair of sharpened ends (see FIGS. 1 and2). The staples referred to are substantially elongated with straightparallel shanks joined by a transverse interconnecting back. It will beapparent how the guideway 27 can be proportioned so that it will readilypass the staples with sliding clearance and will act upon the staples toguide them and the driver blade E. A feature of the cooperative magazineand head construction is the simplified rearwardly open channel-shape ofthe guideway 27 in the head B extending between the top plane ofcylinder head 15 and the front end face 25 of the head. As abovedescribed, the facer 21 engageably receives the rear face 28 of the headB and completes the rectangular cross section of the guideway 27 withdurable hard metal, but only in the area of the head 15. The extension26 has side walls 16' and a front wall 17 complementary to and havingsliding engagement with the walls 16 and 17 above described; therebypositioning the head B in working position in the frame A.

A cylinder C is a sleeve structure that is inserted into the cylinderchamber 12 to reciprocably receive the piston D and in order toestablish a surrounding reservoir 30 adapted to be periodically chargedwith fluid under pressure. In practice, the fluid reservoir 30 is anannulus established between the straight tubular cylinder wall 31 andwall 32 that forms the cylinder chamber 12. Thus, the fluid reservoir 30occupies the circumferential area of the cylinder chamber 12 thatsurrounds the cylinder wall 31. In carrying out the invention, thecylinder C is a simple insert that is pressed into working position withits lowermost end seated in a recess 33 at the bottom of the cylinderchamber 12. A radial flange 34 at the uppermost end of the cylinderslideably engages within the wall 32, and there being a seal at saidfit, as shown. The cylinder C with its uppermost flange 34 ischaracterized by an upwardly faced seat 37 that is cooperatively exposedto the release means G. In the form illustrated, the seat 37 is a flatfaced seat in a plane normal to the axis of the cylinder and adapted tobe engaged by a flat faced and axially reciprocable valve element 50. Inaccordance with the invention, the cylinder C is provided with one ormore openings 38 at or near the lower end of the cylinder wall 31 and/orreservoir 30, said openings remaining in communication with the interiorof the cylinder C at all times, it being sufficient that the piston Ddoes not pass or cross the opening or openings 38.

The piston D operates to reciprocate in the cylinder C and has drivingengagement with the driver blade E to move the driver blade forwardly ordownwardly. The cylinder chamber 12 is supplied with fluid underpressure by a valve means I so as to effect the piston movement ashereinafter described. The piston body 40 is sealed with the cylinderwall 31 by means of an O-ring 41 engaged therein to have substantialfrictional restraint against movement when at rest. However, when saidrestraint is overcome the piston D is free to move in the cylinder C.The piston D is characterized by a depending body portion 42 of reduceddiameter for handling of fluid below the body 40 and for effecting theair return function. The depending body portion 42 is provided with adownwardly disposed face 43 in a plane normal to the piston axis andengageable with the snubber F, and it is this body portion and face 43which pass the cylinder openings 38. Charging of the reservoir 30 iseffected by the provision of a check valve between the cylinder chamberabove and below piston D, and as shown involves a circumferential valveseat 46 in the piston portion 42 and a valve element seated therein inthe form of an elastic O-ring 47, there being ports 48 extending fromthe seat to the top of the piston D. It will be apparent that the valve(46-47) permits charging of the reservoir 30 with fluid under pressure.

The driver blade E is essentially a slender elongate part rectangular incross sectional configuration and terminates at its forward end in aflat fastener or staple driving face 45. The blade E has a lower stapledriving portion at the forward end thereof which occupies the guideway27 of the head B and an upper driven portion 46 at the rear end thereofwhich couples to the piston D. As shown, the piston D is slotted andthere is a pin 44 that positively connects the parts for coupledengagement. In practice, the fit of the driver blade in the guideway 27is not air tight or leak-proof, but it does afford substantialresistance to fluid flow and thereby restricts volume of leakage, acontrolled leakage, especially when related to the short length of timeto which said fit of parts is subjected to the return air pressure.

The snubber F is provided for its expected function of stopping thepiston D and attached driver blade E, and additionally is provided toseal the reservoir 30 during the short period of time when the piston Dand driver blade E are at the lower end of the work stroke. Accordingly,the snubber F is a circular part of substantial depth that surrounds thedriver blade E with clearance and that engages and seals with the wall31 of the cylinder, and which is made of the usual rubber or likeelastomeric material and is formed to provide a seat 58 upon which thepiston body portion 42 is adapted to have flat sealed engagement. It isat this period and point of engagement that the body 40 is held abovethe opening or openings 38 for the access of fluid pressure to theunderside thereof.

The air release means G that may be employed is disclosed in US. Pat.No. 3,026,849entitled FLUID OP- ERATED VALVE FOR RELEASE OF FLUID UNDERPRESSURE, issued Mar. 27, 1962, and is adapted to cooperate with andcontrol operation of the piston D. The means G is provided to releasethe piston D from the upper end of the cylinder C and is move andaccelerate the piston D when sufficient fluid pressure has beenestablished to effect the desired percussive work stroke. The releasemeans G may involve various and suitable mechanisms to carry out thefunction referred to without affecting the present invention. Forexample, the release means F may involve means adapted to shift a valveelement 50 between two positions, one where the supply of air is shutoff to the cylinder C and air exhausted therefrom, and the other wherethe supply of air is admitted to the cylinder C and the exhaust isclosed. The valve seat 37 at the top end of the cylinder C is exposed toand opens into said chambered grip portion 1 1, to be opened and closedby the valve element 50 of means G. The upper end of the cylinder C isclosed by a cap 52, the release means G being carried by and operablethrough said cap, as clearly shown in FIG. 6.

The valve means J is a fluid pressure exhausting means that retains orexhausts operating fluid in or from the release means G and ispreferably formed in and carried by the frame A of the tool and, asshown, there is a three-way valve with a port 53 opening into thepressure chamber, a port 54 open to atmosphere, and a port 55 openingbeneath a piston that lifts the valve elements 50 of means G. A manuallyoperable trigger 57 operates a valve 56 to open port 53 to port 55,whereby the valve element 50 of means G is lifted. The said valveelement of means J is normally closed, being vented to atmospherethrough port 54.

The magazine H which is provided for handling a supply of fasteners tobe received and delivered individually through the head B involves ahousing 60 supported by the frame A and a slide 70 removable from andshiftably carried by said housing. The housing 60 is an elongatedinverted channel that is formed so as to embrace the exteriorconfiguration of the staple S and according to the present invention ithas a top 61 that engages flat against the coplanar bottoms 18 and 18';and it has sides 62 that fit through the mounting lugs 19 to be embracedtherebetween. The front of the housing is secured to the lugs 19 bymeans of ears 63 normal to the sides 62, there being fasteners 64bearing upon the head B and extending therethrough and through the lugs19 and threadedly engaged into the said ears. The forward end of thehousing is normal and in the plane of the rear guideway interior wall,leaving the guideway 27 open and clear for the reception of individualfasteners S and for severance thereof from a stack of said fastenersprogressively advanced into the guideway to be acted upon by the driverblade D. The rear end of the housing 60 is secured to the strut 22 bymeans of a screw fastener 65 threadedly engaged into the strut,preferably through a tab at the top 61 and threaded into the back of thestrut; and in which case the housing extends slightly rearward of thestrut as shown. In order to carry the slide 70, the lower margins of thesides 62 are provided with outwardly turned flanges 66 forming tracks,and there are outwardly turned stops 67 at the rear of the housing,projecting from the sides, to engage a removable abuttment on the slide70.

The slide 70 that is removable from and shiftably carried by the housing60 is an elongated carriage for the stick of fasteners S that is to befed thereby into the guideway 27. The slide 70 comprises a cover plate71 that is coextensive in length with the housing 60 so as to completelyclose the open channel of said housing, and it carries a closure 72 atits front end to completely enclose the guideway 27 to the front endface 25 of the head B. Thus, the slide 70 includes the plate 71, theclosure 72 and a staple rail 73 upon which the stick of fasteners Srides to be pressed forwardly by a follower 74 biased by a spring 75.The closure plate 71 has opposed inwardly open channels that slideablyengage over the outwardly turned flanges 66 of the housing 60, the platebeing disengageable from said flanges by withdrawing the slide 70rearwardly. The head closure 72 and rail 73 terminate in a normal planeat the front end of the slide 70, the closure 72 having a flat face 76engaged with the flat rear face 28 of the head B to complete therectangular cross section of the guideway 27 in the area of the headextending below the cover plate 71 of the magazine. The staple rail 73is comprised of a pair of upstanding parallel walls 77 terminating shortof the strut 22 and extending to the flat front face 76. Said walls 77are spaced inward from the housing top 61 and sides 62, thereby formingan inverted U-shaped passageway for the stick of fasteners S. Thefollower 74 is complementary in cross section to the configuration ofthe staples S and has a normal forward end to engage and move the stickof staples forwardly, being biased by the tension spring 75 anchored atand within the rear portion of the rail and trained over a sheave 75'next adjacent to the front face 76 and attached to the follower. It willbe apparent how the slide 70 is 'retractible so as to be reloaded withsticks of staples S and so as to completely expose the channel of theguideway 27.

In accordance with this invention, l have provided the air biasedmagazine safety lock and guideway closure adjuster means X thatreadjusts during operation of the tool while providing safety for theuser. Referring back to the frame A and chambered grip portion 11, it issignificant that operating air under pressure is accumulated therein andavailable over the strut 22 by providing a passage 80 through said strutand opening into the chambered grip portion. The safety lock and closureX involves, generally, a cylinder 81 and piston 82, a guideway 83 andcrosshead 84, a return spring 85, and a lock bolt 86 and finger grip 87manipulatable to retract the piston 82, crosshead 84 and lock bolt 86. Afeature is the angular disposition of the operational axis of the piston82, crosshead 84 and especially the lock bolt 86 which cooperativelyengages with a rearwardly disposed lock face 88 at the rear of the slide70. In practice, the said operational axis is tipped downwardly andrearwardly at while the face 88 is tipped likewise at there being arelease angle of 10 incorporated in the lock bolt as will be described.The lock face 88 is provided in a part at the rear end of rail 73 whichis solid between the walls 77 thereof and with an inclined top 78 todepress the lock bolt 86 before it is projected against lock face 88.

Referring now to the cylinder 81 and piston 82; the cylinder 81 is ofmoderate diameter as shown and is bored into the grip portion 11 fromthe bottom 18' of the strut 22 with the passage 80 opening into thesame. The piston 82 reciprocates in the said cylinder and has and 0 ringseal 90 to retain the air pressure.

Referring now to the guideway 83 and cross-head 84; the guideway 83 iscounterbored through the strut 22 from the bottom 18' thereof, with ashoulder 91 between the same and the bore of cylinder 81. The crosshead84 is a cylindrical enlargement at the lower end of piston 82 andslideably moves in the guideway 83 to be steadied thereby, and iscorrespondingly of greater diameter than the piston.

The return spring 85 is a light compression spring that surrounds thepiston 81 and presses between the said crosshead 84 and shoulder 91,thereby to urge the piston and crosshead downwardly.

Referring now to the lock bolt 86 and finger grip 87; the lock bolt 86is an element carried by the piston and crosshead to retractibly projectbeyond the bottom 18 and through an oversized opening in the cover plate71 to lockably engage with the lock face 88 on the slide 70. Inaccordance with the invention, the end portion of the lock bolt ischamfered or tapered at an angle of 10 relative to the operational axis.Consequently, the tapered end portion 92 of the lock bolt has linecontact with the lock face 88 being retractile therefrom at an inclinedangle substantially less than a normal angle. The conical shape of theend portion 92 and its mode of contact provides for facility in releasewhile the incline of the operational axis provides for increased wedgedengagement and ready adjustments. The end result in infinitesimaladjustments as circumstances require while retaining the ability tomanually retract the lock bolt 86 at any time. The finger grip or grips87 are provided as a convenience to retract the lock bolt 86 andpreferably a pair of grips carried by the crosshead and exposed atopposite sides of the strut 22. As shown, a bar 94 passes through thecrosshead and is guided in a pair of slots 95 at opposite sides of thestrut, and to which the finger grips are fastened. The grips 87 areflared outwardly for convenient gripping between a persons fingers whenretracting the lock bolt 86.

A removable abutment 100 of plastic or any suitable pliable materialadapted to be bent and/or deformed, embraces the opposite margins of theslide 70, underlying the same, and projecting above the cover plate atopposite sides thereof to engage the stops 67. The underlying portion ofthe abutment 100 has a button 101 engaged in a complementary opening inthe cover plate 71 to locate the same at the forward end of the slide70.

From the foregoing it will be seen that l have provided a uniquemounting for the head B and which accurately maintains the normality ofthe rear face 28 of the head, as is required in order to cooperate withthe flat face 76 of the head closure 72 adjusted thereto by means of themagazine safety lock and guideway closure X. With a stick of fasteners Sinstalled on the staple rail 73, the slide is moved forwardly intooperating position accompanied by withdrawal of the lock bolt 86 toallow passage of the staples and to ride over the inclined top 78 andfollowed by its projection behind and into line contact with the lockface 88. It is significant that the crosshead 84 does not bottom againstthe cover plate 71 through which the lock bolt 86 projects, and to theend that the spring and the air pressured piston 82 forcibly readjustthe said line contact. A light pressure is applied to the means X by thespring 85 for loading the tool before use, while a heavy pressure isapplied to the means X by the air pressure bias. Consequently, the userof the tool must employ considerable force in order to release the lockbolt 86 when air pressure is connected to the tool, a reminder that thetool is active. However, as a facility in reloading or in clearing ajamb, it is a simple matter to disconnect the air pressure supply hose,thereby assuring safety and with no danger of activating the driverblade D.

Having described only a typical preferred form and application of myinvention, 1 do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself anymodifications or variations that may appear to those skilled in the art.

I claim:

1. A head construction and guideway closure for a fastener driving too]wherein a driver blade operates to project individual fasteners from aguideway aligned with a magazine disposed normal thereto and feedingindividual fasteners into the upper portion of said guideway and whereinthe lower portion of said guideway beneath said magazine is a rearwardlyopen channel closed by a closure positioned thereto by a slide on themagazine, and including: a tool frame having a flat bottom and havingspaced depending mounting lugs with coplanar front faces normal to saidbottom and having a window through the said frame and extending betweensaid mounting lugs next adjacent to said coplanar faces thereof; a facerseated in said window and having a front wall parallel with saidcoplanar faces of the mounting lugs; a fastener receiving head carriedby said frame and comprising, a body having a top seat engaged with saidbottom and a rear face engaged with said coplanar front faces offhemounting lugs, a channel-shaped fastener guideway disposed normal to thesaid bottom and between said mounting lugs, and an extension projectingupwardly from the top seat of the body and engaged with said parallelfront wall of the facer in said window of the frame; fastener meanssecuring the head to said mounting lugs; a magazine slide movable in adirection normal to the rear face of the head and having a guidewayclosure with a front face parallel to said rear face of the head; andmeans releasably forcing the said magazine slide and closure positionedthereby into flat interface engagement with the said rear face of thehead and closing the back of the channel-shaped fastener guideway.

2. The head construction and guideway closure for a fastener drivingtool as set forth in claim 1, wherein the said facer overlies the saidcoplanar faces of the mounting lugs and presents a coplanar front wallcontinuing from the first mentioned front wall of the facer andoverlying the said coplanar faces of the mounting lugs, and wherein therear face of said head body engages said continuing coplanar front wallof said facer.

3. The head construction and guideway closure for a fastener drivingtool as set forth in claim 1, wherein the said facer overlies the saidcoplanar faces of the mounting lugs and presents a coplanar front wallcontinuing from the first mentioned front wall of the facer andoverlying the said coplanar faces of the mounting lugs, wherein the rearface of said head body engages said continuing coplanar front wall ofsaid facer, wherein the magazine of the tool engages with said bottom ofthe frame and enters between the said mounting lugs and overlying facerand has a pair of mounting ears projecting laterally therefrom, andwherein the fastener receiving head and the said facer pass mountingfasteners therethrough aligned with and extending through the mountinglugs respectively and through the mounting ears of the magazine, therebyclamping the head and facer and magazine onto said lugs and in workingposition on the frame.

4. A magazine lock in a fluid powered fastener driving tool whereinthere is a head and a driver blade that operates through the head, amagazine disposed normal to the head and feeding individual fastenersinto said guideway, said tool having a frame and a fluid pressure supplythereto and means controllably operated therewith to project fasteners,said magazine having a housing supported in the frame and having aretractile slide movable toward the head to close the housing, said lockcomprising, a cylinder bored in the frame on an axis projectinglaterally from the movement plane of the slide, there being open fluidcommunication between the end of the cylinder remote from the slide andsaid fluid pressure supply, a piston in the cylinder and biased by thepresence of fluid under pressure to move toward the slide, and a lockbolt retractibly shifted by the piston to engage behind a lock face onthe slide to hold the slide toward the head.

5. The magazine lock for a fluid powered fastener driving tool as setforth in claim 4, wherein the end portion of the lock bolt is tapered,and wherein the lock face on the slide is slanted at a correspondingangle to have line contact with said end portion of the lock boltthereby wedging the slide forwardly.

6. The magazine lock for a fluid powered fastener driving tool as setforth in claim 4, wherein the laterally projecting axis of the cylinderand piston and of the lock bolt shifted thereby is slanted to extenddownwardly and rearwardly toward the slide thereby facilitating releaseof said lock bolt.

7. The magazine lock for a fluid powered fastener driving tool as setforth in claim 4, wherein the end portion of the lock bolt is taperedand the laterally projecting axis of the cylinder and piston and of thelock bolt shifted thereby is slanted to extend downwardly and rearwardlytoward the slide, and wherein the lock face on the slide is slanted at acorresponding angle to have line contact with said end portion of thelock bolt thereby releasably wedging the slide forwardly.

8. The magazine lock for a fluid powered fastener driving tool as setforth in claim 4, wherein the end portion of the lock bolt is tapered 10to its axis and the laterally projecting axis of the cylinder and pistonand of the lock bolt shifted thereby is slanted 5 from a normal to themovement plane of the slide to extend downwardly and rearwardly towardthe slide, and wherein the lock face on the slide is slanted at acorresponding 15 angle to have line contact with said end portion of thelock bolt thereby releasably wedging the slide forwardly.

9. The magazine lock for a fluid powered fastener driving tool as setforth in claim 4, wherein manually engageable means is coupled to thelock bolt to retract the same.

10. The magazine lock for a fluid powered fastener driving tool as setforth in claim 4, wherein a crosshead of larger diameter than the pistoncouples the said piston and lock bolt and to steady the latter, whereinthe frame is counterbored to slideably guide the crosshead, and whereina compression spring pressures between the crosshead and a shoulder atthe juncture of the cylinder bore and said counterbore.

11. The magazine lock for a fluid powered fastener driving tool as setforth in claim 4, wherein a crosshead of larger diameter than the pistoncouples the said piston and lock bolt and to steady the latter, whereinmanually engageable means is accessible through at least one slot intosaid counterbore to retract said lock bolt, wherein the frame iscounterbored to slideably guide the crosshead, and wherein a compressionspring presses between the crosshead and a shoulder at the juncture ofthe cylinder bore and said counterbore.

12. The magazine lock for a fluid powered fastener driving tool as setforth in claim 4, wherein the fastener driving tool has an elongatedgrip portion spaced above and extending laterally of the head and with astrut at its remote end having supporting engagement with the housing ofthe magazine, and wherein the lock comprising the cylinder and pistonand lock bolt is accommodated in said strut, the lock face on the slidebeing at the rear end portion thereof.

13. The magazine lock for a fluid powered fastener driving tool as setforth in claim 4, wherein the fastener driving tool has an elongatedgrip portion spaced above and extending laterally of the head and with astrut at its remote end having supporting engagement with the housing ofthe magazine, and wherein the cylinder bore of the lock extends throughthe strut with said open fluid communication into said grip portioncharged therewith, the lock face on the slide being at the rear endportion thereof.

14. The magazine lock for a fluid powered fastener driving too] as setforth in claim 4, wherein the fastener driving tool has an elongatedgrip portion spaced above and extending laterally of the head and with astrut at its remote end having supporting engagement with the housing ofthe magazine, and wherein the cylinder bore of the lock extends throughthe strut and is slanted at an angle extending downwardly and rearwardlytoward the slide and with said open fluid communication into said gripportion charged therewith, and wherein the end portion of the lock boltis tapered and wedgedly engages the lock face on the slide.

1. A head construction and guideway closure for a fastener driving toolwherein a driver blade operates to project individual fasteners from aguideway aligned with a magazine disposed normal thereto and feedingindividual fasteners into the upper portion of said guideway and whereinthe lower portion of said guideway beneath said magazine is a rearwardlyopen channel closed by a closure positioned thereto by a slide on themagazine, and including: a tool frame having a flat bottom and havingspaced depending mounting lugs with coplanar front faces normal to saidbottom and having a window through the said frame and extending betweensaid mounting lugs next adjacent to said coplanar faces thereof; a facerseated in said window and having a front wall parallel with saidcoplanar faces of the mounting lugs; a fastener receiving head carriedby said frame and comprising, a body having a top seat engaged with saidbottom and a rear face engaged with said coplanar front faces of themounting lugs, a channel-shaped fastener guideway disposed normal to thesaid bottom and between said mounting lugs, and an extension projectingupwardly from the top seat of the body and engaged with said parallelfront wall of the facer in said window of the frame; fastener meanssecuring the head to said mounting lugs; a magazine slide movable in adirection normal to the rear face of the head and having a guidewayclosure with a front face parallel to said rear face of the head; andmeans releasably forcing the said magazine slide and closure positionedthereby into flat interface engagement with the said rear face of thehead and closing the back of the channel-shaped fastener guideway. 2.The head construction and guideway closure for a fastener driving toolas set forth in claim 1, wherein the said facer overlies the saidcoplanar faces of the mounting lugs and presents a coplanar front wallcontinuing from the first mentioned front wall of the facer andoverlying the said coplanar faces of the mounting lugs, and wherein therear face of said head body engages said continuing coplanar front wallof said facer.
 3. The head construction and guideway closure for afastener driving tool as set forth in claim 1, wherein the said faceroverlies the said coplanar faces of the mounting lugs and presents acoplanar front wall continuing from the first mentioned front wall ofthe facer and overlying the said coplanar faces of the mounting lugs,wherein the rear face of said head body engages said continuIng coplanarfront wall of said facer, wherein the magazine of the tool engages withsaid bottom of the frame and enters between the said mounting lugs andoverlying facer and has a pair of mounting ears projecting laterallytherefrom, and wherein the fastener receiving head and the said facerpass mounting fasteners therethrough aligned with and extending throughthe mounting lugs respectively and through the mounting ears of themagazine, thereby clamping the head and facer and magazine onto saidlugs and in working position on the frame.
 4. A magazine lock in a fluidpowered fastener driving tool wherein there is a head and a driver bladethat operates through the head, a magazine disposed normal to the headand feeding individual fasteners into said guideway, said tool having aframe and a fluid pressure supply thereto and means controllablyoperated therewith to project fasteners, said magazine having a housingsupported in the frame and having a retractile slide movable toward thehead to close the housing, said lock comprising, a cylinder bored in theframe on an axis projecting laterally from the movement plane of theslide, there being open fluid communication between the end of thecylinder remote from the slide and said fluid pressure supply, a pistonin the cylinder and biased by the presence of fluid under pressure tomove toward the slide, and a lock bolt retractibly shifted by the pistonto engage behind a lock face on the slide to hold the slide toward thehead.
 5. The magazine lock for a fluid powered fastener driving tool asset forth in claim 4, wherein the end portion of the lock bolt istapered, and wherein the lock face on the slide is slanted at acorresponding angle to have line contact with said end portion of thelock bolt thereby wedging the slide forwardly.
 6. The magazine lock fora fluid powered fastener driving tool as set forth in claim 4, whereinthe laterally projecting axis of the cylinder and piston and of the lockbolt shifted thereby is slanted to extend downwardly and rearwardlytoward the slide thereby facilitating release of said lock bolt.
 7. Themagazine lock for a fluid powered fastener driving tool as set forth inclaim 4, wherein the end portion of the lock bolt is tapered and thelaterally projecting axis of the cylinder and piston and of the lockbolt shifted thereby is slanted to extend downwardly and rearwardlytoward the slide, and wherein the lock face on the slide is slanted at acorresponding angle to have line contact with said end portion of thelock bolt thereby releasably wedging the slide forwardly.
 8. Themagazine lock for a fluid powered fastener driving tool as set forth inclaim 4, wherein the end portion of the lock bolt is tapered 10* to itsaxis and the laterally projecting axis of the cylinder and piston and ofthe lock bolt shifted thereby is slanted 5* from a normal to themovement plane of the slide to extend downwardly and rearwardly towardthe slide, and wherein the lock face on the slide is slanted at acorresponding 15* angle to have line contact with said end portion ofthe lock bolt thereby releasably wedging the slide forwardly.
 9. Themagazine lock for a fluid powered fastener driving tool as set forth inclaim 4, wherein manually engageable means is coupled to the lock boltto retract the same.
 10. The magazine lock for a fluid powered fastenerdriving tool as set forth in claim 4, wherein a crosshead of largerdiameter than the piston couples the said piston and lock bolt and tosteady the latter, wherein the frame is counterbored to slideably guidethe crosshead, and wherein a compression spring pressures between thecrosshead and a shoulder at the juncture of the cylinder bore and saidcounterbore.
 11. The magazine lock for a fluid powered fastener drivingtool as set forth in claim 4, wherein a crosshead of larger diameterthan the piston couples the said piston and lock bolt and to steady thelatter, wherein manually engageable means is accessible through at leastone slot into said counterbore to retract said lock bolt, wherein theframe is counterbored to slideably guide the crosshead, and wherein acompression spring presses between the crosshead and a shoulder at thejuncture of the cylinder bore and said counterbore.
 12. The magazinelock for a fluid powered fastener driving tool as set forth in claim 4,wherein the fastener driving tool has an elongated grip portion spacedabove and extending laterally of the head and with a strut at its remoteend having supporting engagement with the housing of the magazine, andwherein the lock comprising the cylinder and piston and lock bolt isaccommodated in said strut, the lock face on the slide being at the rearend portion thereof.
 13. The magazine lock for a fluid powered fastenerdriving tool as set forth in claim 4, wherein the fastener driving toolhas an elongated grip portion spaced above and extending laterally ofthe head and with a strut at its remote end having supporting engagementwith the housing of the magazine, and wherein the cylinder bore of thelock extends through the strut with said open fluid communication intosaid grip portion charged therewith, the lock face on the slide being atthe rear end portion thereof.
 14. The magazine lock for a fluid poweredfastener driving tool as set forth in claim 4, wherein the fastenerdriving tool has an elongated grip portion spaced above and extendinglaterally of the head and with a strut at its remote end havingsupporting engagement with the housing of the magazine, and wherein thecylinder bore of the lock extends through the strut and is slanted at anangle extending downwardly and rearwardly toward the slide and with saidopen fluid communication into said grip portion charged therewith, andwherein the end portion of the lock bolt is tapered and wedgedly engagesthe lock face on the slide.